Electrical device



Nov. 16, 1937. A. LAMPL ELECTRICAL DEVICE Original Filed Sept. 24, 1926INVENTOR. 5C

ATTORNEY.

Patented Nov. 16, 1937 UNITED STATES PATENT OFFICE ELECTRICAL DEVICEAlfred Lampl, Berlin, Germany ma Electric Corporation,

assignor to Nor- New York, N. Y., a

March 11, 1932, Serial No. 599,149. many March 13, 1926 (Cl. 17H!)ICInim.

This invention relates to electrical devices such as lamps, sockets andthe like articles.

It is particularly directed to electrical devices having shunts acrossthe terminals thereof, particularly of the type wherein the fusing oririttlng properties of comminuted, granulated, chipped 0r powderedmetallic material and the reduction of the resistance of said shuntabove certain limits of voltage is utilized for the control andvariation of the electrical devices.

The present application is a division of my application, Serial No.137,802, filed September 24, 1926, for. Electrical resistances, whichmatured into Patent No. 1,878,153, issued September 20,

ll 1932. Said application Serial No. 137,602, was copending with myapplication Serial No. 68,042, filed November 9, 1925, which maturedinto Patent No. 1,692,272, issuedNovember 20, 1928, and which wasreissued as Reissue Patent No. 18,495

on June 14, 1932. This application forms a continuation in part of saidPatent No. 1,692,272 reissued as Reissue Patent No. 18,495. In my saidpatent there is described a resistance for serially mounted lamps in theshape of powdered granules or chips forming a normally non-conductingshunt to be used for example, for serially connected incandescent lamps.As stated in my said patent, upon the breaking down of a translatingdevice, such as the filament of one of a series of lamps provided withsaid shunt, an automatic overbrldglng of the point of interruption isproduced since the ,total voltage of the series is impressed on theparticular shunt causing a fritting, partialor imperfect fusing, of thegranules into as a conducting fritted mass, and the interruption of thecurrent at the other serially arranged current consuming device is thusavoided.

After the defective lamp has been replaced, the particular shunt hasgenerally been Jarred or 40 shaken up to unfrit the particles and renderthe shunt again non-conductive.

It is an object of my invention to provide means for obviatin'g thenecessity for shaking or knocking the resistance against an object tounfrit the shunt and to automatically render the shunt againnon-conductive. I accomplish this object by embedding the metallicgranules, metal chips or metal powder in a solid binding material,

50 which by itself is not an electrical conductor, such for instance, asgypsum, chamotte, burnt clay, concrete, cement, mortar and the like. Bythis means, electrical resistances or shunts may be obtained whicheither present a very considerable electric resistance coeillcient, orare adapt- Divided and this application In Gered, to oppose a certaindefinite degree of resistance to the passage of current in accordancewith the voltage at the terminals of the resistance, depending uponwhether the voltage is above or below a certain limit, that is, thefritting limiting voltage, or the voltage at ,which fritting of theparticles occurs.

In other words, it is an object of my invention to provide an electricalsystem in which a plurality of lamps are attached to sockets connectedin series circuit, and to provide either the lamps at the bases thereofor the sockets, with shunts which are normally non-conductive at thevoltage of each device, but which automatically become conductive at thevoltage of the series and which will automatically again becomenon-conductive upon reduction of the voltage from that of the series tothat of the individual device, without shaking or vibrating the devicesor the shunts, so that the i'ritted mass automatically becomes unfrittedupon reduction of the voltage.

A further object of this invention is to incorporate a shunt of thecharacter described in the base of an electric lamp or other electricaldevices having spaced terminals, and which may be connected in seriescircuit.

A still further object of this invention is to provide electricaldevices such as lamps and the like, which shall be of economicalconstruction and practical and efilcient to a high degree in use.

Other objects of this invention will in part be obvious and in parthereinafter pointed out.

The invention accordingly consists in the features of construction,combinations of elements, and arrangement of parts which will beexemplifled in the construction hereinafter described, and of which thescope of application will be indicated in the following claim.

In the accompaying drawing, in which is shown one of the variouspossible illustrative embodiments of this invention, I

Fig. 1 is an axial cross-sectional view of an electric lamp embodyingthe invention; and

Fig. 2 is a fragmentary, axial, cross-sectional view of a lamp embodyingthe invention and il lustrating a modified construction thereof.

In Fig. 1 there is shown an electric lamp it having a base II and a bulbl2. Attached to the base II is a rear insulating disc l3 to which thereis attached the usual central contact H. The filament II is connected onone side thereof, as at it, to the metallic screw shell Ii, and theopposite end of the filament is connected as at II to the centralcontact I. Disposed within the shell is a small axial tubular metallicmemher I electrically interconnected by means of wire it or metallicstrip to the central contact ll. Between the screw threaded shellportion of the base H and the metal tube I is a resistance shunt la.normally non-conductive at a low voltage of the lamp Ill and whichautomatically becomes conductive at the higher voltage of a series ofthe lamps when said lamps are connected together in series circuit andwhich will automatically become non-conductive again when the voltage isreduced to that of the lamp. The resistance or shunt la may likewise becomprised of metal particles such as for instance of particles of brass,iron, aluminum and may further be secured in an embedding material. Theentire mass may be introduced into the base of the lamp in pasty orplastic condition and allowed to solidify in the base. Obviously, anyother suitable resistance having properties above mentioned, may besubstituted for the resistance lw.

In the form shown in Fig. 2, the lamp 20 is likewise provided with abase 2| and a bulb 2!. Embedded within the neck portion 23 of the bulb22 is a resistance lb substantially similar to the resistances l and la.One end of the filament H for the lamp 20 is connected to the resistanceor shunt lb and to the screw threaded metallic shell portion of the base2|. The other end of the filament likewise extends through theresistance lb and is connected to the central contact of the lamp. Theresistance lb is protected by a special ballast resistance 21 which maybe in the form of a metallic filament oi. resistance wire ofsubstantially the same resist ance as the incandescent filament 2l. Theresistance 21 has one and embedded within the resistance lb and theother end thereoi is connected to the filament 2t.

In accordance with the arrangement shown in Fig. 2 of the drawing, thesensitive fritted resistance lb is protected against excessive strain bythe fixed ballast resistance 21 so that the resistance lb merelyoperates as a sensitive fritting valve and therefore may be selected ofrelatively small size.

It' will of course, be understood that the invention is not limited tothe few forms of appli cations and embodied herewith shown anddescribed, merely by way of illustration of the principle thereof, butmay be utilized for various other equivalent purposes and changes inconstruction. Thus, other suitable resistances or shunts havingproperties set forth above may be substituted for the resistances la orlb and said shunts may be applied to a plurality of other electricaldevices, not shown in the drawing. For example, as stated in my saidre-issue patent, loosely aggregated particles of chips of iron, nickelor other metal may be disposed between the electrodes of a lamp in thebase or glass body of said lamp. I

As various possible embodiments might be made oi the above invention,and as various changes might be made in the embodiment above set forth,it is to be understood that all matter herein set forth or shown in theaccompanying drawing is to be interpreted as illustrative and not in alimiting sense.

Having thus described my invention, I claim as new and desire to secureby Letters Patent:

An electric lamp comprising a base, a bulb attached thereto, a filamentwithin the lamp having theends thereof connected to the terminals of thebase, a shunt within the lamp across said filament, normallynon-conducting below a predetermined voltage, and adapted to becomeautomatically conducting above said voltage, and 9. ballast resistancehaving one end embedded within said shunt and the other end. thereofconnected electrically to said filament.

ALFRED LAMPL.

CERTIFICATE OF CORRECTION.

Patent No. 2,0995505.

November 16, 1937. ALFRED LAIlPL.

It is hereby certified that the name of the assignee in the abovenumbered patent was erroneously written and printed as "Norma liileotrioCorporation" whereas said name-should have been written and printed asNomaElectric Corporation, of New York, N.Y., a corpora-'- tion of NewYork, as shown by the re'cord of assignments in this of-, fies; and thatthe said Letters Patent shduld be read with this correction therein thatthe same may conform to the record of the case.

in the Patent Office.

Signed and sealed this 25th day of January, A. D. 1958.

(Seal) Henry Van Arsdale, Acting Commissioner of Patents.

